• Journal of Korean Society of Forest Science
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• v.77 no.4
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• pp.453-459
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• 1988

The purposes of this study were to evaluate the effects of acid rain on tree growth and on the mycorrhizal formation and the effects of mycorrhizae on the host tolerance to acid rain. Simulated acid rain was applied for five months to Pinus $rigida{\times}taeda$ seedlings in pots inoculated with Pisolithus tinctorius (Pt) and Suillus luteus (Sl). Mycelial inocula of Pt and Sl were either mixed with entire pot soil (Mix) or casted as a band (Band) after soil sterilization. Three pH levels of acid rain (pH 3.0, 4.5 and 6.4 adjusted by 3 : 1 mixture of sulfuric and nitric acids) were tested. Pt-Mix was most effective in growth stimulation and resulted in 45-90% increase in tree height in sandy loam. Pt-Band was less effective than Pt-Mix in growth stimulation and mycorrhizal formation. Simulated acid rain at pH 4.5 stimulated height growth by 10-55%, while acid rain at pH 3.0 did not significantly affect the height growth. The top/root ratio was increased by pH 4.5 treatment, while pH 3.0 treatment reduced it. Mycorrhizal infection rate was not affected by acid rain. Pt inoculation reduced acid-induced leaf injury by 28-58% in both pH 3.0 and 4.5 compared with un-inoculated plants. Sl was also effective in growth enhancement, but was less effective than Pt in both mycorrhizal infection and reducing leaf injury.

• Journal of Korean Society of Forest Science
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• v.66 no.1
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• pp.82-94
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• 1984

The variation of stomatal density and stomatal length of four species of oaks was studied for the purpose of examining the differences among populations and among individual trees within population. Nine populations of Quercus mongolica, four populations of Q. serrata and Q. variabilis respectively, and three populations of Q. acutissima were selected in the natural stands of oaks distributed through the whole country. Twelve leaves were sampled from each of 20 trees from each population. The length of 20 stomata and ten replications of stomatal density were measured from collodion replicas of each leaf under a microscope. Average stomatal densities and lengths ranged through $600-1000/mm^2$ and $19-26{\mu}m$ respectively in all of the species studied. The stomatal densities and lengths presented significant differences statistically at the level of 1 or 5% among populations and among individual trees within population in all the species. Quercus mongolica, especially, showed large variation among populations, while Q. variabilis did very narrow variation compared to the other species. The coefficients of variation of stomatal densities and lengths among individual trees within population exhibited small values of 3.7-12.0% and 1.4-5.3% respectively in all the populations of the species. The average stomatal densities of Q. mongolica showed statistically significant correlation of multiple correlation coefficient of $R_{df{\cdot}2.6}=0.868^*$ and multiple regression equation of $Y=0.041X_1(G.M.T.S.)+0.489X_2(G.M.H.S.)+22.37$ with the sum of growing season mean daily temperature and the sum of growing season mean daily humidity of the stand studied. However the average stomatal lengths showed no relation with the same meteological variables. The figures of frequency distribution of the measurements of leaves or the mean values of individual trees did not show normal distribution curves in some populations. The curves, as well as the results of ANOVA, exhibited the differences among populations.

• Journal of Korean Society of Forest Science
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• v.90 no.2
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• pp.169-175
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• 2001

Genomic DNAs were extracted from the leaves of 182 ginkgo trees (Ginkgo biloba L.) planted in 6 regions and subjected to the analysis of both I-SSR and RAPD markers. A total of 227 amplicon variants were generated by PCR using 15 I-SSR primers and 67 amplicons by PCR with 5 RAPD primers. Levels of genetic diversity within 6 populations were turned out to be similar (Shannon's Index, I-SSR : 0.35~0.40; mean of 0.38, RAPD : 0.31~0.38; mean of 0.35, combined : 0.35~0.40; mean of 0.37). Ranks of the level of genetic diversity estimated from I-SSR, RAPD, and combined data were not coincided each other. Majority of genetic diversity was allocated among individuals within populations (I-SSR : 94.31%, RAPD : 93.62%, combined : 93.57%), which resulted in pretty low level of population differentiation. Genetic differentiation between male and female groups was turned out to be quite low (I-SSR : 0.03, RAPD : 0.091, combined : 0.043), which slightly fluctuated when analysis was restricted to the data obtained from 3 regions where both male and female trees were sampled (I-SSR : 0.038, RAPD : 0.084, combined : 0.047). Genetic relationships among the populations, reconstructed by UPGMA, were not coincided with geographic affinity, which might be resulted from sharing of seed sources in some regions. Whereas independent cluster analyses with I-SSR data and RAPD data, respectively, reclassified by sexes revealed two sexual groups in which all the male and the female populations were clustered together, cluster analysis with combined data did not show clear sexual grouping.

• Journal of Korean Society of Forest Science
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• v.87 no.1
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• pp.90-97
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• 1998

This study was carried out to compare the characteristics of relative conductivity(RC) in the twenty-one deciduous broad-leaved species. The results obtained were summarized as follows : 1. The RC ranged from $3.18{\times}10^{-15}$ to $1.23{\times}10^{-10}m^2$ in deciduous broad-leaved species, and appeared different values in various portions of a tree and species. 2. In eight diffuse-porous species, the ranges of average RC were $3.49{\times}10^{-13}$ to $6.35{\times}10^{-11}m^2$ in stems. $4.89{\times}10^{-13}$ to $2.99{\times}10^{-11}m^2$ in branches, and $1.33{\times}10^{-13}$ to $9.42{\times}10^{-12}m^2$ in junction part between stem and branch. In thirteen ring-porous species, the RCs were $7.14{\times}10^{-13}$ to $4.76{\times}10^{-11}m^2$ in stems, $2.93{\times}10^{-13}$ to $3.91{\times}10^{-11}m^2$ in branches, and $1.14{\times}10^{-13}$ to $9.20{\times}10^{-12}m^2$ in junction part. 3. The RC and diameter of stem have no interrelation in eight diffuse-porous species. The RC of stem increased with decreasing diameter of stem in eleven ring-porous species except Fraxinus mandshurica and Maackia amurensis. 4. In five deciduous broad-leaved species, the RC of 1-year-old shoots(the leader and adjacent laterals ) ranged from $4.87{\times}10^{-13}$ to $8.41{\times}10^{-11}m^2$ in the leaders, and $7.93{\times}10^{-14}$ to $2.01{\times}10^{-11}m^2$ in the adjacent laterals. The RCs were much greater in the leaders than in the adjacent laterals because of the hydraulic dominance of the leader shoot.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.502-516
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• 1995

The objective of this study was to estimate throughfall, stemflow, interception loss and net rainfall in relation to rainfall interception, and to understand the factors affecting interception process at Pinus taeda stand and Pinus densiflora stand in the Research Forests of Seoul National University, located in Choosan, Kwangyang, Chollanamdo. 1. The gross rainfall during the period of field observation was 3,107.6mm(average 1,035.9mm/year). Most of the daily rainfall intensity was under 30mm, which was 90% in 1992, 81% in 1993 and 88% in 1994. 2. In this study the throughfall, stemflow, interception loss and net rainfall were expressed separately as a function of gross rainfall. The overall throughfall collected during the period of field observation was 2,432.5mm(78.3%) at Pinus taeda stand and 2,699.6mm at Pinus densiflora stand, out of total rainfall of 3107.6mm. The canopy storage capacity, which was determined by the prediction equation between gross rainfall and throughfall was 1.1mm at Pinus taeda stand and 1.3mm at Pinus densiflora stand. 3. The sums of stemflow from measurement of total rainfall at Pinus taeda stand and Pinus densiflora stand was 227.3mm(7.3%) and 62.7mm(2.0%), respectively. The minimum rainfall causing stemflow was estimated as 7.2mm at Pinus taeda stand and 1.9mm at Pinus densiflora stand. 4. Interception loss accounted for 447.8mm(14.4%) at Pinus taeda stand and 345.3mm(11.1%) at Pinus densiflorra stand. 5. Net rainfall was 2,659.8mm(85.6%) at Pinus taeda stand and 2,762.3mm(88.9%) at Pinus densiflora stand. 6. The rates of throughfall and stemflow increased with increasing the gross rainfall. However, the amounts of throughfall and the stemflow were constant above 30mm at Pinus taeda stand and 50mm at Pinus densiflora stand. The rates of interception loss decreased with increasing the gross rainfall. However, the amount of interception loss was constant above 50mm at Pinus taeda stand and Pinus densiflora stand.

• Journal of Korean Society of Forest Science
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• v.81 no.3
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• pp.247-254
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• 1992

Vegetational data obtained from 50 quadrats of Mt. Jungwangsan area were analysed by applying two multivariate methods : two-way indicator species analysis(TWINSPAN) for classification and detrended canonical correspondence analysis(DCCA) for ordination. DCCA technique allowed to extract the ordination axes that could be related to 15 environmental factors. The forest vegetation in Mt. Jungwangsan was classified into Quercus mongolica-Tilia amurensis, Quercus mongolica-Rhododendron schlippenbachii, Quencus mongolica-Kalopanax pictus, Quercus mongolica-Carpinus cordata, Quercus mongolica-Cornus controversa, Betula costata, Fraxinus mandshurica, and Ulmus laciniata communities according to the TWINSPAN. The relationships between the distribution of dominant species of forest vegetation and soil condition in Mt. Jungwangsan were investigated by analyzing elevation and soil nutrition gradient. Ulmus laciniata, Betula costata, and Fraxinus mandshurica forest were distributed in a ravine of the low elevation and in the good nutrition area of $Mg^{{+}{+}}$, total nitrogen, and $Ca^{{+}{+}}$, Quercus mongolica groups in the high elevation and in the poor nutrition area. Quercus mongolica-Kalopanax pictus forest of Quercus mongolica groups was distributed in the high elevation and in the good nutrition area of $Ca^{{+}{+}}$, C.E.C., $Mg^{{+}{+}}$, and total nitrogen, Quercus mongolica-Rhododendron schlippenbachii forest in the low elevation and poor nutrition area. Quercus mongolica-Carpinus cordata forest and Quercus mongolica-Cornus controversa forest were distributed in the medium elevation and medium nutrition area. The two dominant factors influencing community distribution were elevation and topography.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.321-326
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• 2011

The aim of the present study was to investigate antihyperglycemic effect of Gleditschiae Spina (GS) in streptozotocin (STZ)-nicotinamide (NA)-induced type 2 diabetic rats. The rats were divided into four groups: normal control (NC), diabetic control (DC), diabetic rats supplemented with acarbose (AC, 4 mg/kg), and with GS ethanol extracts (GSE, 50 mg/kg). Weekly fasting blood glucose (FBG) for 10 weeks and oral glucose tolerance test (OGTT) at 10th week were monitored using glucose oxidase-peroxidase reactive strips. The FBG level was significantly reduced in AC group after 8 weeks and in GSE group at the end of period. The AUCs for the glucose response from OGTT and blood glucose level after sacrifice were significantly lower in the AC and GSE groups than the DC group. GSE supplementation significantly increased plasma total radical-trapping antioxidant potential (TRAP) in STZ-NA-induced diabetic rats, compared with DC group. The present study indicates that GSE could ameliorate type 2 diabetes and be comparable to acarbose, a standard hypoglycemic drug. Also, we suggest that GSE may possess antioxidant activity against the STZ-NA-induced oxidative stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1562-1568
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• 2011

We studied the amounts of trans fatty acids and saturated fatty acids in child-favored foods. Confectioneries, breads, donuts and hamburgers were included in this study. The total fatty acid content and the amount of each type of fatty acid were determined by gas chromatography with a flame-ionized detector. Confectioneries were shown to have the highest content of crude fat. The mean content was 24.2${\pm}$6.9 (range: 4.6~41.1) g/100 g food. The mean content of crude fat in donuts, bread and hamburgers was 23.9${\pm}$5.8 (range: 14.1~39.5) g/100 g food, 15.7${\pm}$7.9 (range: 1.4~30.0) g/100 g food, and 9.5${\pm}$3.4 (range: 4.5~18.5) g/100 g food, respectively. Bread had the most trans fatty acids at 1.3 g/100 g food. This result inferred that manufacturers have tried to reduce the trans fat content. The mean content of saturated fatty acids in confectioneries, donuts, bread, and hamburgers was 11.6${\pm}$4.8 (range: 2.0~22.7) g/100 g food, 11.2${\pm}$4.0 (range: 4.8~23.2) g/100 g food, 6.9${\pm}$4.1 (range: 0.6~15.4) g/100 g food, 3.0${\pm}$1.0 (range: 1.0~5.8) g/100 g food, respectively. This content depended on crude fat. The composition of fatty acids varied according to the oil and fat used in the manufacturing process of each food, and the natural content. Foods that were fried in vegetable oil tended to be especially low in saturated fat.

• Journal of Korean Society of Forest Science
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• v.81 no.3
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• pp.273-279
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• 1992

Protoplasts isolated from leaf mesophyll tissues of Populus koreana ${\times}$ P. nigra var. italica were fused with those of P. euramericana cv. Guardi. Well expended healthy leaves of 5 to 7 week-old-plantlet grown in vitro were used as source materials. Leaves from P. koreana ${\times}$ P. nigra var. italica and P. euramericana cv. Guardi were digested in enzyme solution I (2.0% Cellulase, 1.2% Hemicellulase, 0.4% Macrozyme, 2.0% Driselase, 0.05% Pectolyase ; w/v) and enzyme solution II (1.0% Cellulase, 1.2% Hemicellulase, 0.4% Macrozyme, 2.0% Driselase, 0.05% Pectolyase ; w/v), respectively, The highest frequency of fusion among the protoplasts originated from the two source materials was approximately 21% using 40% PEG or 15% dextran. In addition, fusion frequency was enhanced by incorporating 30mM of $Ca^{2+}$ in eluting solution at pH 10.5. Dividing cells and/or mint-calli were obtained by culturing the fusion products in a liquid 8p-KM medium supplemented with 0.6M sucrose, $0.45{\mu}M$ 2, 4-D, and $0.5{\mu}M$ BA. Shoots were regenerated from the fusion product-derived calli after culture on MS medium containing $5.0{\mu}M$ zeatin. To verify the putative hybrid or cybrid, SDS-PAGE was carried out. From the 24 regenerants, just two plants showed intermediate protein band patterns compared with those of the original source plants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.283-289
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• 2011

The preference and satisfaction for Korean food by Chinese students studying at Mokpo National University of Korea were surveyed. The students (n=167) were 53.9% males, 58.1% Korean residents for 6 months and 47.9% in healthy condition. The recognition of Korean food was highly light taste ($3.36{\pm}0.95$) and the preference of Korean food materials was in the order of beef (46.7%), hairtail fish (28.7%), baechu (24.4%), tangerine (49.1%), milk (38.9%) in each food category. Eating habits were feeling of hunger on reason for eating (43.1%), moderate satiety degree for a diet (58.7%), no time for reason to skip diet (48.5%), family for impact factor of eating habits (55.1%) and irregular diet time for the problem of eating habits (40.1%). The recognition of Korean food menu was in the order of baechukimchi, bulgogi, ggakdugi, samgyupsal, ddeokbokki, galbitang, and gomtang; the preference order was bulgogi, doejigalbijjim, soegalbijjim, dakgalbijjim, samgyupsal, galbitang, and dakdoritang. The recognition and preference of Korean food menu were significant in bibimbap, tteokguk, doenjang jjigae, kimchi jjigae, ddeokbokki, japchae, baechukimchi, and ggakdugi (p<0.001), as well as jeonbokjuk, bibimguksu, soegalbijjim, doejigalbijjim, dakgalbijjim, saengseonmaeuntang, gomtamg (p<0.01), hobakjuk, bulgogi, and dakdoritang (p<0.05). The actual dormitory foodservice was twice daily (47.3%), <10~20 min for diet time (65.3%). The reason for using university foodservice was compulsory diet (37.1%) whereas the reason of not using university foodservice was tastelessness (45.5%); kimchi was the most leftover (27.5%). According to foodservice quality attribute, the importance and satisfaction were the highest in hygienic part. Foodservice quality attribute was significant between importance and satisfaction in all items except location of facilities foodservice (p<0.001).